Burden and Risk of Asthma and Rhinitis in Atopic Dermatitis: Global Estimates from a Hierarchical Bayesian Model

Abstract Background Atopic dermatitis (AD) is a chronic inflammatory skin disease often associated with asthma and rhinitis. However, epidemiological evidence on these comorbidities remains fragmented and is largely limited to high-income countries. Objective To provide comprehensive global, regional, and country-level estimates of the prevalence and odds ratios (ORs) of asthma, rhinitis, and their subtypes among individuals with AD. Methods We systematically reviewed 278 studies from PubMed, EMBASE, Web of Science, and CNKI. Standardized prevalence eastimate and ORs were derived using a Bayesian hierarchical linear mixed-effects model. Results Among individuals with AD, the global prevalence estimate of asthma, rhinitis, allergic rhinitis, rhinoconjunctivitis, and coexisting asthma and rhinitis was 20.1% (from 2.5% in Israel to 59.4% in India), 45.1% (from 7.8% in Israel to 82.7% in India), 41.4% (from 6.8% in Israel to 80.3% in India), 30.7% (from 4.3% in Israel to 71.9% in India), and 10.4% (from 1.1% in Israel to 40.8% in India), respectively. Estimate were higher when restricted to AD cases diagnosed by dermatologists or physicians. The highest comorbid prevalence was observed in India, Cuba, Finland, and Puerto Rico. Compared with healthy controls, AD was associated with higher odds of asthma (OR 2.73, from 1.59 in China to 6.64 in Ethiopia), rhinitis (OR 2.98, from 1.73 in China to 7.23 in Ethiopia), allergic rhinitis (OR 2.42, from 1.41 in China to 5.89 in Ethiopia), rhinoconjunctivitis (OR 4.21, from 2.45 in China to 10.19 in Ethiopia), and coexisting asthma and rhinitis (OR 2.42, from 1.41 in China to 5.89 in Ethiopia). Conclusion This study provides the first globally standardized estimates of respiratory comorbidities in AD, and can inform clinical practice and public health policy.